Vabiable ctjt-off gear fob steam-ehgines



BENNET HOTCHKISS, OF NEW HAVEN, CONNECTICUT.

VARIABLE CUT-OFF GEAR FOR STEAM-ENGINES.

To all whom it may concern:

Be it known that I, BENNET HoTcHKIss, of the city and county of NewHaven, in the State of Connecticut, have invented a new and usefulImprovement in Cut-Offs for Steam-Enginesg and I do hereby declare thatthe following is a full, clear, and exact description of theconstruction, character, and operat-ion of the same, reference being hadto the accompanying drawings, which make a part of this specification,in which- Figure l is a perspect-ive view of the cutoff apparatus,showing the manner of tripping the valve, etc. Fig. 2 is a section ofthe rod and arm which lift the rod, or stem, of the valve, showing theirconnection with the tripping lever.

My improvement consists in the method of tripping` the valve .stem bythe use of an inclined plane on the end of a collar which is adjusted bythe operation of the governor on a sliding bar, by means of a diagonalslot, in such a manner that the admission of the steam into the cylinderwill be cut off at any desired portion of the stroke of the piston,exactly in accordance with t-he velocity of the governor.

I make the rod, A, and arm, B, (to raise the valve stem,) of iron, orany other suitable material, substantially, as shown in Fig. l, and, onthe lower end of the rod, A, Iv fix a foot, or projecting piece, asshown at a, which enables 'the cam-shaped toe, b, on the rock-shaft, C,to raise the rod, and with it the arm, B, which is connected with thevalve stem, c, as-shown in Fig. 2, and indicated by dots at c, Fig. 1.

In the upper portion of the valve stem, c, I make a recess, as shown atal, Fig. 2, (where the stem moves freely in arm, B,) and, to the arm, B,I attach a lever, c, Figs. 1, and 2, which works on a joint pin, orfulcrum, at g. The inner end of this lever, c, is pressed into therecess, d, in the valve stem, c, as shown in section in Fig. 2, by theaction of a spring, as seen at 7L, Figs. l, and 2, (substantially as inF. E. Sickless patent.) To trip this valve stem, c, I erect a standard,D, Fig. l, through which I cut, or make, two mortises, at right angleswith each other, through one of which the sliding bar, E, passes, asshown in Fig. l, and through the other, the pin, 7c, works, to elevate,or depress, the collar, F.

I make the collar, F, Fig. l, as a hollow cylinder to move freely on thestandard, D, with a mortise through it to admit the bar, E, to pass toelevate, or depress it,y (by means of the pin, la) and at its lower end,I form an inclined plane, as shown at m, Fig. l, to act upon the lever,c, to trip the valve, and cut off the steam, at the proper time.

I make the flat, or sliding bar, E, Fig. l, with an inclined, ordiagonal, mortise, or slot, as shown at a, Fig. l, through which thepin, le, passes to sustain the collar, F, in the required position;-and, as the pin, 7c, works in the mortise in the standard, D, (asbecollar, F, will be depressed in proportion to the place the pin, lc,occupies in the inclined slot, or mortise, a. To cause this bar, E, tomove freely, and steadily, I erect another standard, at Gr, through themortise in which one end of the bar passes, as shown in Fig. l.

To work the valve gear, I use a common rock-shaft, as shown at C, Fig.l, worked in the usual way, as by the lever K, or by any other meansfound to be convenient.

I use the common governor, or any other similar regulator.

To use my improvement, I connect the governor with the end, L, of thesliding bar, E, adjust the whole to the speed and power required, andset the engine in motion in the usual way. Then, when the balls of thegovernor expand, by the increased velocity, they will move the bar, E,in the direction indicated by the dart, which will cause the inclinedslot, a, to act upon the pin, 7c, and force down the collar, F, so thatthe lever, e, will come in contact with the inclined plane, m, at a lessheight, and the valve will be tripped, and the steam shut olf, at a lessportion of the stroke of the piston, so as to regulate the induction ofthe steam to the quantity required to produce the necessary power. Thus,it will require no attention from the engineer, however frequently thebelts may be thrown off, or how much the heat varies, while there isenough steam generated to afford the greatest power needed for themachinery.

The advantages of my improvement consist in the simplicity of the meansused to render itself regulating. And in the eXactness of the regulationof its movements by That I claim as my invention, and desire to secureby Letters Patent, 1s-- The Combination of the sliding bar,-E, 15

with the sliding collar, F, when constructed, arranged, and made tocontrol the time of the cut-o-i, by the operation of the governor, orregulator only, substantially as herein described.

BENNET HOTCHKISS. Witnesses:

S. THOMPSON, R. FITZGERALD.

